Compositions comprising an epoxy resin, shellac, polybutadiene and a peroxide curingagent



United States Patent ce Jaff figl a phenol having at least two phenolic hydroxy groups 3,228,901 such as bis-(4-hydroxy phenyl)-2,2-propane. United COMPOITIONS COMPRISING AN EPOXY RESIN, States Patents 2,494,295; 2,500,600 and 2,511,913 de- SHELLAC POLYBUTADIENE AND A PEROXIDE scribe further epoxy resins which can be used in conjunc- Ral p li G li fv i s ittsfield Mass assignor to General 5 l with my invention .above.pat.ents are hereby Elec'mc comany a g of New York incorporated by reference in this application. The epoxy No Drawing. riieiise t. 11, 1961,Ser.No.137,060 T651115 harem have more than one epoxr group p 6 Cl i ((31, 250-47) molecule. They can be prepared by reacting a polyhydroxy alcohol or phenol such as hydroquinone, resor- This invention relates to new and improved resinous 1O cinol, glycerine and condensation products of phenols compositions. More particularly, it relates to resinous with ketones, for example, bis-(4-hydroxy phenyl)-2,2-

compositions which are useful as electrical insulation propane with epichlorohydrin. The reaction of epimaterial, for coating, impregnating, bonding and laminatchlorohydrin with bis-(4-hydroxy phenyl)-2,2-propane ing purposes which are characterized by improved physical is as follows:

CH; 1 alkali H0 OH C1CH2-CE/CH2 CH3 0 i CH: I (13H: OHzCHCHz-OC JOO-CHT(EH-CHZOO(EOCH CHTEH \O/ L (3H3 OH 'n CH3 0 qualities and especially by superior adhesive qualities where n has an average value ranging from 0 to about and flexibility. 10. Such ethoxyline resins are sold under the name The use of improved epoxy resins as electrical insulatof Epon, under the name Araldite, as ERL resins, and ing material for certain applications has been described as Epi-Rez resins. The data given below for such resins in Patents 2,769,739 and 2,899,399, assigned to the same is representative. assignee as this patent describing the use of composi- TABLE I tions comprising epoxy resins and shellac. Certain ,deficiencies of the epoxy resins using the familiar acidic or Epoxy resin Epoxide equivalent; M.P., 0. basic catalysts were overcome by the use of shellac which combined chemically to form a cured resin. How- Epon 822 102 9 ever, in some applications the epoxy resin-shellac com- E383 @33 33 :5 32 3333 positions described in the above patents are not charac- 35 Epoi11007 1, 000-1, 900 127-133 terized by the degree of flexibility which is often required 333 188?: 123,2 @233 along with excellent adhesive bond. 300 375 I iio-gisd It is a principal object, therefore, of this invention to 200-205 Liguid provide resinous compositions for electrical insulating, Emma 510 E333 bonding, laminating and coating purposes which will have the desirable characteristics of epoxy resin-shellac Among other useful epoxy resins are those based on composltlons but at the Same f W111 F posses sed other glycidyl type materials as Well as those based on of Physlcal ruggedness and especlauy Supenor adheslve aliphatic radicals including oxidized polyolefins among ness and flexibility when thermoset which is not attain- Others able with prior materials. The alkali metal-polymerized polybutadiene used in Briefly, the present invention relates to resinous coinconnection ith th present i ti contains an posi s mpri ing, y g 100 Parts Of P Y resin, preciable percentage or about 40 percent of 1,2-butadiene from to 250 parts shellac, and from 10 to 100 parts polymer and is thus polmerizable by means of the usual of alkali metal-polymerized polybutadiene, plus from 1 50 vinyl polymerization type catalysts, among which are to 15 percent of curing agent for said polybutadiene barium peroxide, sodium peroxide, benzoyl peroxide, based on the weight of the polybutadiene. From 1 to ternary butyl PQ dicumyl Peroxide, tertiary 10 parts of dicyandiamide can also be used to provide butyl f p f 31110113 Others Whlch are n wn to improved bond Strength The present materials are those skilled in the art which react above the softening resistant to the usual solvents and are, therefore, best ap- Pomt of Present 9 plied as hot melt materials, and in this role are partic- In carrylilg out.the lnventl9n the polybuuldlene cured ularly useful in impregnating, bonding, and coating paper or polymerized with an alkali metal or alkali metal type talyst is milled as on hot rolls along with the e oxy and paper-like materials, paper board, cloth and porous ca P materials in general. resin and the shellac, the order of addition of the various mater'al t th The epoxy resins used in COIl]l.lI1C'[l0I1 with my invenl S o 8 rolls not bung of any Partlcular con v sequence. When the materials are thoroughly admixed, are known In the am They are descnbed the vinyl polymerization catalyst is added. The result- C aH United States Patents 2,324,483 and 2,444,333, ant material, when cooled, is very brittle and can readily it Pgtents 9 Generally, the be applied as a hot melt material to the desired base. epoxy resins described therein are the reaction product From 1 to 10 art of di yandiamide can also be cmof an epihalogenohydrin such as epichlorohydrin and 5 ployed to further enhance the bond strength. After application, the composition is cured at a temperature of 125 C. to 175 C. for one-quarter hour to four hours and preferably at a temperature of about 150 C. for one-quarter to one hour at 120 C. for from one half to four hours, it being realized that this curing process is of a time-temperature nature. The cured material is very tough and adherent and is characterized by good impact strength and desirable flexibility. The following examples illustrate the practice of the invention, it being realized that many other applications will occur to those skilled in the art.

Example 1 There were milled on hot rolls heated to a temperature of about 100 C., 25 parts of sodium polymerized butadiene with which were blended 100 parts of Epon 1004 and 67 parts of shellac. After a homogeneous composition was attained, three parts of dicumyl peroxide were added and thoroughly mixed with further rolling. The material was removed from the mill and cooled at which point it was rather brittle. This brittle material was melted and hot coated on paper which was laid up into a laminate of layers about 0.1 inch in total thickness. The laminate so formed was cured for one hour at 150 C. to provide a firmly bonded laminate which was somewhat flexible and was particularly characterized by its toughness.

' Example 2 There were mixed on hot rolls 25 parts of sodium polymerized butadiene, 223 parts of shellac and 100 parts of Epon 1004 as in Example 1, with three parts ofdicumyl peroxide added after a homogeneous mix was attained. The product was used to treat paper laminae as in Example 1. Again, the laminate when cured at 150 C. for one hour produced a very hard and tough product, the laminae showing very good adhesion and flexibility.

Example 3 Example 1 was repeated using 100 parts of sodium polymerized butadiene, 100 parts of shellac, 100 parts of Epon 1004 and 11 parts of dicumyl peroxide. Once again, the resulting product was hot melted, applied to paper which was laid up into a laminate 0.1 inch thick. The laminate so formed and cured for one hour at 150 C. was more brittle than the products of Examples 1 and 2 but still very useful.

Example 4 There were mixed on hot rolls 25 parts of sodium polymerized butadiene, 100 parts of dewaxed shellac and 100 parts of Epon 1007 as in Example 1. Then, 2.5 parts of dicumyl peroxide and 2.5 parts of dicyandiamide were blended into the homogeneous mix and the product was removed and cooled. The dicyandiamide contributes to the bonding strength of the composition. Paper was coated with the above composition by a hot melt process and pressed at 200 psi. into laminates about 50 mils thick and cured for 40 minutes at 150 C. The finished laminate was flexible, tough and excellently bonded.

There are provided then by this invention laminating compositions and laminates prepared therefrom which are useful inpreparinglayer insulation for electrical purposes, flat laminates for various structural purposes, wound or laminated cylinders, transformer coils and the like, such structures being characterized not only by superior adhesiveness but by such flexibility as to absorb mechanical shock Without destruction.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A composition of matter comprising, by weight, parts of epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups, from 50 to 250 parts shellac and from 10 to 100 parts of alkali metal-polymerized polybutadiene along with a peroxide curing agent for said polybutadiene.

2. A composition of matter comprising, by weight, 100 parts of epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups, from 50 to 250 parts shellac, from 10 to 100 parts of alkali metal-polymerized polybutadiene, a peroxide curing agent for said polybutadiene and from 1 to 10 parts of dicyandiamide.

3. A composition of matter comprising, by Weight, 100 parts of epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups containing epoxide groups, 223 parts shellac, 25 parts of alkali metal polymerized polybutadiene containing 1,2-butadiene polymer and a peroxide curing agent for said polybutadiene.

4. A composition of matter comprising, by weight, 100 parts epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups containing epoxide groups, 100 parts shellac, 100 parts of alkali metal polymerized polybutadiene containing 1,2-butadiene polymer and a peroxide curing agent for said polybutadiene.

5. A composition of matter comprising, by weight, 100 parts of epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups containing 1,2-epoxide groups, 67 parts shellac and 25 parts of alkali metal polymerized polybutadiene containing 1,2-butadiene polymerand a peroxide curing agent for said polybutadiene.

6. A composition of matter comprising, by weight, 100 parts of epoxy resin comprising the reaction product of an epihalogenohydrin and a phenol having at least two hydroxy groups, 100 parts shellac, 25 parts of alkali metal-polymerized polybutadiene, 2.5 parts of a peroxide curing agent for said polybutadiene and 2.5 parts of dicyandiamide.

References Cited by the Examiner UNITED STATES PATENTS 2,769,739 11/1956 Flowers et al. 260-24 2,886,473 5/1959 Schroeder 260-837 2,899,399 8/1959 Flowers 260--24 2,985,632 5/ 1961 Willis 260-27 FOREIGN PATENTS 517,816 2/ 1940 Great Britain.

736,457 9/1955 Great Britain.

841,203 6/1960 Great Britain.

OTHER REFERENCES Whitby: Synthetic Rubber, Wiley & Sons, 954, N.Y., pp. 289-299.

Delmonte: The Technology of Adhesives, 1947, Reinhold ub. Corp., N.Y., pp. 217-218.

WILLIAM H. SHORT, Primary Examiner.

ALFONSO D. SULLIVAN, Examiner.

I. ZIEGLER, S. N. RICE, Assistant Examiners. 

1. A COMPOSITION OF MATTER COMPRISING, BY WEIGHT, 100 PARTS OF EPOXY RESIN COMPRISING THE REACTION PRODUCT OF AN EPIHALOGENOHYDRIN AND A PHENOL HAVING AT LEAST TWO HYDROXY GROUPS, FROM 50 TO 250 PARTS SHELLAC AND FROM 10 TO 100 PARTS OF ALKALI METAL-POLYMERIZED POLYBUTADIENE ALONG WITH A PEROXIDE CURING AGENT FOR SAID POLYBUTADIENE. 